I am an owner of an Oceanis 411 which I purchased out of the charter fleet in the BVI. Your question is pretty general in scope, but depending on the type of sailing will determine what to look for in terms of equipment. Purchasing my boat our of the charter industry required immediate upgrades in electronics, i.e. Chart Plotter & radar, additionally we had to get additional safty gear such as ephir and liferaft. Mine is a 2002 model, which we love but my rigging needed inspection and repairs prior to cruising from PR
to Trinidad. Last year before cruising to Vz I replaced my chainplates. They were badly damaged but I found some rust, so I opted to replace them. I just completed my three year survey and will be replacing mu cutlass bearing, zincs on my propeller and my lower rudder bearing. All in all no major repairs but depending of the age of the boat you are looking at these were my major items. Nothing major has broken while we have been cruising, but I am aggresssive with preventative care. I can share other info if you need it.
Since I've purchased the boat out of the charter fleet, my next project is to upgade my house bank to a 400AH system and install a H/O alternator and DCmonitoring/maintenance system. This may not be a concern for you. By the way, I love the boat for coastal cruising.